Resistive memory and methods of processing resistive memory

ABSTRACT

Resistive memory and methods of processing resistive memory are described herein. One or more method embodiments of processing resistive memory include conformally forming a cell material in an opening in an interlayer dielectric such that a seam is formed in the cell material, forming a conductive pathway by modifying the seam, and forming an electrode on the cell material and the seam.

TECHNICAL FIELD

The present disclosure relates generally to semiconductor memory devicesand methods, and systems, and more particularly, to resistive memory andmethods of processing resistive memory.

BACKGROUND

Memory devices are typically provided as internal, semiconductor,integrated circuits in computers or other electronic devices. There aremany different types of memory, including random-access memory (RAM),read only memory (ROM), dynamic random access memory (DRAM), synchronousdynamic random access memory (SDRAM), flash memory, and resistive, e.g.,resistance variable, memory, among others. Types of resistive memoryinclude programmable conductor memory, phase change random access memory(PCRAM), and resistive random access memory (RRAM), among others.

Memory devices are utilized as non-volatile memory for a wide range ofelectronic applications in need of high memory densities, highreliability, and low power consumption. Non-volatile memory may be usedin, for example, personal computers, portable memory sticks, solid statedrives (SSDs), digital cameras, cellular telephones, portable musicplayers such as MP3 players, movie players, and other electronicdevices.

Memory devices may include a number of memory cells arranged in amatrix, e.g., array. For example, an access device, such as a diode, afield effect transistor (FET), or bipolar junction transistor (BJT), ofthe memory cells may be coupled to an access line, e.g., word line,forming a “row” of the array. The memory elements of each memory cellmay be coupled to a data line, e.g., bit line, in a “column” of thearray. In this manner, the access device of a memory cell may beaccessed through a row decoder activating a row of memory cells byselecting the word line coupled to their gates. The programmed state ofa row of selected memory cells may be determined, e.g., sensed, bycausing different currents, to flow in the memory elements depending onthe resistance associated with a programmed state for a particularmemory cell.

Memory cells may be programmed, e.g., written, to a desired state. Thatis, one of a number of programmed states, e.g., resistance levels, canbe set for a memory cell. For example, a single level cell (SLC) canrepresent one of two logic states, e.g., 1 or 0. Resistive memory cellscan also be programmed to one of more than two programmed states, suchas to represent more than two binary digits, e.g., 1111, 0111, 0011,1011, 1001, 0001, 0101, 1101, 1100, 0100, 0000, 1000, 1010, 0010, 0110,or 1110. Such cells may be referred to as multi state memory cells,multi-digit cells, or multilevel cells (MLCs).

Resistive memory such as RRAM may store data by varying the resistancelevel of a resistive memory element. Data may be programmed to aselected RRAM cell by applying sources of energy, such as positive ornegative electrical pulses, e.g., positive or negative voltage orcurrent pulses, to a particular resistive memory element for apredetermined duration. RRAM cells may be programmed to a number ofresistance levels by application of voltages or currents of variousmagnitudes, polarities, and durations.

Methods for processing, e.g., fabricating, RRAM cells may include planarfabrication of RRAM cells. That is, RRAM cells may have a planarstructure. However, RRAM cells having a planar structure may be large,e.g., RRAM cells having a planar structure may increase the size of anRRAM device. Further, RRAM cells having a planar structure may operateinconsistently or erroneously, e.g., the sensed resistance level of anRRAM cell having a planar structure may be different than the resistancelevel to which that cell was programmed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1G illustrate process steps associated with forming a resistivememory cell in accordance with a number of embodiments of the presentdisclosure.

FIG. 2 illustrates a functional block diagram of a resistive memory inaccordance with a number of embodiments of the present disclosure.

DETAILED DESCRIPTION

Resistive memory and methods of processing resistive memory aredescribed herein. One or more method embodiments of processing resistivememory include conformally forming a cell material in an opening in aninterlayer dielectric such that a seam is formed in the cell material,forming a conductive pathway by modifying the seam, and forming anelectrode on the cell material and the seam.

Processing resistive memory, e.g., resistive memory cells, in accordancewith a number of embodiments of the present disclosure can decrease thesize of the resistive memory cells and/or memory devices associated withthe resistive memory cells. Processing resistive memory in accordancewith a number of embodiments of the present disclosure can also increasethe consistency and reliability of the resistive memory. For example,processing resistive memory in accordance with embodiments of thepresent disclosure can decrease the number of erroneous data readsassociated with resistive memory.

In the following detailed description of the present disclosure,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration how a number of embodimentsof the disclosure may be practiced. These embodiments are described insufficient detail to enable those of ordinary skill in the art topractice a number of embodiments of this disclosure, and it is to beunderstood that other embodiments may be utilized and that process,electrical, or mechanical changes may be made without departing from thescope of the present disclosure.

As will be appreciated, elements shown in the various embodiments hereincan be added, exchanged, and/or eliminated so as to provide a number ofadditional embodiments of the present disclosure. In addition, as willbe appreciated, the proportion and the relative scale of the elementsprovided in the figures are intended to illustrate the embodiments ofthe present invention, and should not be taken in a limiting sense. Asused herein, “a number of” something can refer to one or more suchthings. For example, a number of memory devices can refer to one or morememory devices.

FIGS. 1A-1G illustrate process steps associated with forming a resistivememory cell in accordance with a number of embodiments of the presentdisclosure. FIG. 1A illustrates a schematic cross-sectional view of aninterlayer dielectric 104 on an electrode 102, with an opening 106 ininterlayer dielectric 104. Electrode 102 can be, for example, tungstenor platinum. Interlayer dielectric 104 can be, for example, an oxidedielectric, such as silicon dioxide (SiO₂). Interlayer dielectric 104could also be, for example, a nitride dielectric, such as siliconnitride (Si₃N₄). Embodiments of the present disclosure are not limitedto a particular type of interlayer dielectric material or electrode.

Interlayer dielectric 104 can be formed on electrode 102 in a number ofways, including chemical vapor deposition (CVD) or atomic layerdeposition (ALD), as will be appreciated by one of skill in the art. Aportion of interlayer dielectric 104 can then be removed, e.g., etchedand/or patterned, to form opening 106. Opening 106 is adjacent toelectrode 102, as shown in FIG. 1.

In a number of embodiments, opening 106 can have a diameter of 10 to 30nanometers. For example, opening 106 can have a diameter ofapproximately 22 nanometers, approximately 25 nanometers, orapproximately 27 nanometers. However, embodiments are not limited to aparticular diameter for opening 106.

FIG. 1B illustrates a schematic cross-section view of the structureshown in FIG. 1A after a subsequent processing step. FIG. 1B includes aresistive memory cell material 108 formed on interlayer dielectric 104and in opening 106 in interlayer dielectric 104. In a number ofembodiments, resistive memory cell material 108 can be conformallyformed on interlayer dielectric 104 and in opening 106. Resistive memorycell material 108 can be conformally formed on interlayer dielectric 104and in opening 106 in a number of ways, including ALD, CVD, and plating.Further, the method of conformal formation can include having a portionof resistive memory cell material 108 that is in bottom up fill orselective mode. However, embodiments of the present disclosure are notlimited to a particular method of conformal formation. The method ofconformal formation used can depend on, for example, the material usedfor resistive memory cell material 108.

Resistive memory cell material 108 can be, for example, a resistancerandom access memory (RRAM) cell material. RRAM cell materials caninclude, for example, Ge_(x)Se_(y), a binary metal oxide such asCu_(x)O_(y), WO_(x), Nb₂O₅, Al₂O₃, Ta₂O₅, TiO_(x), ZrO_(x), Ni_(x)O, andFe_(x)O, and/or other materials that can support solid phase electrolytebehavior. Other RRAM cell materials can include perovskite oxides suchas doped or undoped. SrTiO₃, SrZrO₃, and BaTiO₃, colossalmagnetoresistive materials such as Pr_((1-x))Ca_(x)MnO₃ (PCMO),La_((1-x))CaxMnO₃ (LCMO), and Ba_((1-x))Sr_(x)TiO₃, and polymermaterials such as Bengala Rose, AlQ₃Ag, Cu-TCNQ, DDQ, TAPA, andFluorescine-based polymers, among other types of RRAM cell materials.

In a number of embodiments, resistive memory cell material 108 can beconformally formed, e.g., conformally deposited, on interlayerdielectric 104 and in opening 106 such that a seam, e.g., seams 110-1and 110-2 shown in FIG. 1B, is formed in resistive memory cell material108. As shown in FIG. 1B, the seam can be an opening in resistive memorycell material 108, e.g., a region where the opposite sides of resistivememory cell material 108 approach each other such that resistive memorycell material 108 does not completely fill opening 106. That is,resistive memory cell material 108 can be formed on interlayerdielectric 104 and in opening 106 such that resistive memory cellmaterial conforms to interlayer dielectric 104 and forms a seam inresistive memory cell material 108. In a number of embodiments, the seamformed in resistive memory cell material 108 can be modified to form aconductive pathway in resistive memory cell material 108, as will befurther described herein.

FIG. 1B illustrates a first and a second seam, e.g., seams 110-1 and110-2, that can result from conformal formation of resistive memory cellmaterial 108 in accordance with a number of embodiments of the presentdisclosure. As shown in FIG. 1B, seams 110-1 and 110-2 have differentcharacteristics. Differentiating characteristics can include surface, ornear surface, modification as part of the terminating portion of adeposition procedure.

The characteristics of the seam formed in resistive memory cell material108 can depend on the amount of time for which the conformal formationof resistive memory cell material 108 occurs. For example, the diameterand/or depth of the seam can decrease as the amount of time for whichthe conformal formation of resistive memory cell material 108 occursincreases. In the embodiments illustrated in FIG. 1B, the amount of timefor which the conformal formation that results in the formation of seam110-1 occurs can be greater than the amount of time for which theconformal formation that results in the formation of seam 110-2 occurs.For example, the diameter d1 of seam 110-1 is less than the diameter d2of seam 110-2, as will be further described herein. Additionally, thedepth D1 of seam 110-1 is less than the depth D2 of seam 110-2, e.g.,bottom portion 112-2 of seam 110-2 is closer to electrode 102 thanbottom portion 112-1 of seam 110-1, as shown in FIG. 1B.

In a number of embodiments, resistive memory cell material 108 can beconformally formed in opening 106 such that there is resistive memorycell material 108 between the bottom of the seam and electrode 102,e.g., such that the seam is not in contact with electrode 102. Forexample, as shown in FIG. 1B, seams 110-1 and 110-2 are conformallyformed such that there is resistive memory cell material 108 betweenbottom portions 112-1 and 112-2 of seams 110-1 and 110-2, e.g., suchthat seams 110-1 and 110-2 are not in contact with electrode 102.

The distance between the bottom of the seam and electrode 102 can dependon the amount of time for which the conformal formation of resistivememory cell material 108 occurs. For example, the distance between thebottom of the seam and electrode 102 can increase as the amount of timefor which the conformal formation of resistive memory cell material 108occurs increases. In the embodiments illustrated in FIG. 1B, the amountof time for which the conformal formation that results in the formationof seam 110-1 occurs can be greater than the amount of time for whichthe conformal formation that results in the formation of seam 110-2occurs. For example, the distance between bottom portion 112-1 andelectrode 102 is greater than the distance between bottom portion 112-2and electrode 102, as shown in FIG. 1B. In a number of embodiments, thedistance between the bottom of the seam and electrode 102 can be in therange of 3 Angstroms to 15 Angstroms. However, embodiments of thepresent disclosure are not so limited. For example, the distance betweenthe bottom of the seam and electrode 102 can be up to 100 Angstroms.

FIG. 1C illustrates a schematic top view of resistive memory cellmaterial 108 having seams 110-1 and 110-2 formed therein. That is, FIG.1C illustrates a schematic top view of the conformal formations ofresistive memory cell material 108 shown in FIG. 1B. As shown in FIG.1C, the diameter d1 of seam 110-1 is less than the diameter d2 of seam110-2.

In a number of embodiments, the seam formed in resistive memory cellmaterial 108, e.g., seams 110-1 and 110-2, can have a diameter of 0.5 to5.0 nanometers. For example, the seam can have a diameter ofapproximately 1 nanometer. The diameter of the seam can be measured, forexample, at the top of the seam.

The characteristics of the seam formed in resistive memory cell material108, e.g., the depth and/or diameter of the seams, and/or the distancebetween the bottom of the seam and electrode 102, can result from theconformal formation of resistive memory cell material 108 on interlayerdielectric 104 and in opening 106, in accordance with a number ofembodiments of the present disclosure. However, these characteristics ofthe seam may not be achievable using previous approaches, e.g., planarfabrication.

FIG. 1D illustrates a schematic cross-sectional view of the structureshown in FIGS. 1B and 1C after a subsequent processing step. FIG. 1Dincludes a filament 114 formed on resistive memory cell material 108 andin, e.g., within, a seam 110 in resistive memory cell material 108.Filament 114 can be a modifier material that is a different materialthan resistive memory cell material 108 and/or forms a conductivepathway in seam 110 such that seam 110 is a conductive pathway. That is,forming filament 114 in seam 110 can modify seam 110 to form aconductive pathway in resistive memory cell material 108. Filament 114can be, for example, a metal, such as silver and copper, or a metaloxide, such as copper oxide and silver oxide. That is, filament 114 canbe, for example, a metal, such as copper and silver, that is readilyoxidized or reduced in solid phase. Filament 114 can be part of anadditional, e.g., top, electrode structure, such as electrode 116described in connection with FIG. 1G.

In a number of embodiments, filament 114 can be a filament sourcematerial. That is, filament 114 can contain atoms that can form afilament within resistive memory cell material 108.

Filament, e.g., filament source material, 114 can be formed on resistivememory cell material 108 and in seam 110 in a number of ways, includingspin-coating, spray, ALD, CVD, and condensation. Forming filament sourcematerial 114 in seam 110 can increase the concentration of atoms infilament source material 114. Because the concentration of atoms infilament source material 114 can be increased, filament source material114 can be a thin material, e.g., filament source material 114 can havea thickness that is less than the thickness of resistive memory cellmaterial 108, as shown in FIG. 1D.

As shown in FIG. 1D, filament source material 114 can be formed in seam110 such that an end of filament source material 114 is adjacent tobottom portion 112 of seam 110. Because the end of filament sourcematerial 114 can be adjacent to bottom portion 112 of seam 110, therecan be resistive memory cell material 108 between the end of filamentsource material 114 and electrode 102, filament source material 114 maynot be in contact with electrode 102, and/or the distance between theend of filament source material 114 and electrode 102 can be in therange of 3 Angstroms to 15 Angstroms. Filament source material 114 canalso be formed in seam 110 such that filament source material 114completely fills seam 110, as shown in FIG. 1D.

In a number of embodiments, filament source material 114 can be heatedafter it is formed on resistive memory cell material 104 and in seam110. Heating filament source material 114 can diffuse atoms fromfilament source material 114 into resistive memory cell material 104.

As previously described herein, forming filament source material 114 inseam 110 can modify seam 110 to form a conductive pathway in resistivememory cell material 108. This conductive pathway can be formed withoutforming any additional material between the end of filament sourcematerial 114 and bottom electrode 102 to couple the end of filamentsource material 114 to bottom electrode 102. Rather, the conductivepathway can include a conductive path that extends through region 115 inresistive memory cell material 108, along a path from the end offilament source material 114 to bottom electrode 102. That is, theconductive pathway can be formed with only resistive memory cellmaterial 108 formed between the end of filament source material 114 andbottom electrode material 102, e.g., with only resistive memory cellmaterial 108 in region 115.

FIG. 1E illustrates a schematic cross-sectional view of the structureshown in FIG. 1D after a subsequent processing step. In FIG. 1E, aportion of resistive memory cell material 108 and a portion of filamentsource material 114 are removed. The removed portions of resistivememory cell material 108 and filament source material 114 can beremoved, e.g., etched and/or patterned, in a number of ways, includingchemical mechanical polishing (CMP) and blanket etching.

The removed portion of resistive memory cell material 108 can include,for example, the portion of resistive memory cell material 108 that isnot in opening 106. The removed portion of filament source material 114can include, for example, the portion of filament source material 114that is not in seam 110. Removing these portions of resistive memorycell material 108 and filament source material 114 can expose interlayerdielectric 104, as shown in FIG. 1E.

FIG. 1F illustrates a schematic top view of FIG. 1E. In a number ofembodiments, filament source material 114 can have a diameter d of 0.5to 5.0 nanometers. For example, filament source material 114 can have adiameter d of approximately 1 nanometer. The diameter d of filamentsource material 114 can correspond to the diameter of seam 110. Forexample, in embodiments in which filament source material 114 completelyfills seam 110, the diameter d of filament source material 114 cancorrespond to the diameter of seam 110 at the top of seam 110.

FIG. 1G illustrates a schematic cross-sectional view of the structureshown in FIGS. 1E and 1F after a subsequent processing step. FIG. 1Gincludes an electrode 116 formed on interlayer dielectric 104, resistivememory cell material 108, and filament source material 114. Electrode116 can be, for example, tungsten or platinum. Electrode 116 can beformed, e.g., deposited and patterned, on interlayer dielectric 104,resistive memory cell material 108, and filament source material 114 ina number of ways, as will be appreciated by one of skill in the art. Ina number of embodiments, filament source material 114 can be part of thestructure of electrode 116, as previously described herein.

The structure illustrated in FIG. 1G can be a component, e.g., portion,of a resistive memory cell. For example, the structure illustrated inFIG. 1G can be a component of an RRAM cell, e.g., memory cell 212 shownin FIG. 2.

Resistive memory cells, e.g., RRAM cells, processed in accordance with anumber of embodiments of the present disclosure can decrease the size ofthe resistive memory cells and/or memory devices associated with theresistive memory cells. Resistive memory cells processed in accordancewith a number of embodiments of the present disclosure can also haveincreases consistency and reliability. For example, resistive memorycells processed in accordance with a number of embodiments of thepresent disclosure can have increased reliability as compared to memorycells processed in accordance with previous approaches, e.g., planarfabrication.

As one example, the distance between bottom portion 112 of seam 110 inresistive memory cell material 108, e.g., the end of filament sourcematerial 114, and electrode 102, can be in the range of 3 Angstroms to15 Angstroms, as previously described herein, which can decrease thesize of the resistive memory cell. This distance can also improve theperformance of filament source material 114, which can increase theconsistency and reliability of the resistive memory cell, e.g., memorycell 212 shown in FIG. 2. This distance can result from the conformalformation of resistive memory cell material 108 on interlayer dielectric104 and in opening 106, in accordance with a number of embodiments ofthe present disclosure. However, this distance may not be achievableusing previous approaches, e.g., planar fabrication.

Additionally, opening 106 can have a diameter of 10 to 30 nanometers, aspreviously described herein. Further, seam 110 in resistive memory cellmaterial 108, e.g., filament source material 114, can have a diameter of0.5 to 5.0 nanometers, as previously described herein. These dimensionscan also decrease the size of the resistive memory cell. Thesedimensions can result from the conformal formation of resistive memorycell material 108 and interlayer dielectric 104 and in opening 106, inaccordance with a number of embodiments of the present disclosure.However, these dimensions may not be achievable using previousapproaches, e.g., planar fabrication.

Resistive memory cells processed in accordance with a number ofembodiments of the present disclosure can also decrease the effect ofgrain boundaries in resistive memory cell material 108. For example,resistive memory cell material 108 may contain grain boundaries, andfilament source material 114 may diffuse faster along the grainboundaries. However, embodiments of the present disclosure can restrictthe grain boundary interaction area to the central point of filamentsource material 114, e.g., the central point of seam 110 in resistivememory cell material 108. This can reduce failures associated with thegrain boundaries, which can increase the consistency and reliability ofthe resistive memory cell. This grain boundary area interactionrestriction can result from the conformal formation of resistive memorycell material 108 on interlayer dielectric 104 and in opening 106, inaccordance with a number of embodiments of the present disclosure.However, this grain boundary area interaction restriction may not beachievable using previous approaches, e.g., planar fabrication.

FIG. 2 illustrates a functional block diagram of a resistive memory 200in accordance with a number of embodiments of the present disclosure. Asshown in FIG. 2, resistive memory 200 includes resistive memorystructure 202. Resistive memory structure 202 can be a structureprocessed in accordance with a number of embodiments of the presentdisclosure. For example, resistive memory structure 202 can be thestructure illustrated in FIG. 1G.

In FIG. 2, access device 210 is coupled in series with resistive memorystructure 202 to form memory cell 212. Memory cell 212 is coupled todata line, e.g., bit line, 220 and source line 222. Access device 210can serve as a switch for enabling and disabling current flow throughresistive memory structure 202. Access device 210 can be, for example, atransistor, such as a field effect transistor (FET) or bipolar junctiontransistor (KIT), with a gate coupled to access line, e.g., word line,224. Thus, when word line 224 is energized, access device 210 can beturned on, thereby completing the circuit between source line 222 andbit line 220 through resistive memory structure 202.

In a number of embodiments, bit line 220 and source line 222 are coupledto logic for sensing, e.g., reading, from, and logic for programming,e.g., writing, memory cell 212. For example, as shown in FIG. 2,read/write control multiplexer 230 has an output coupled to bit line220. Read/write control multiplexer 230 can be controlled by read/writecontrol logic line 232 to select between a first input coupled tobipolar write pulse generator 226, and a second input coupled to readsensing logic 228. The magnitude, polarity, and/or duration of voltageor current applied to resistive memory structure 202 for programming canbe controlled by application thereof between bit line 220 and sourceline 222 associated with memory cell 212.

In a number of embodiments, during a write operation, bias generator 229can establish, through bipolar write pulse generator 226, a write biasvoltage potential difference between bit line 220 and source line 222,e.g., a fixed voltage, associated with memory cell 212. The write biasvoltage can cause a particular magnitude of current to flow throughresistive memory structure 202, which can change the resistance ofresistive memory structure 202 to a particular resistance. Theparticular resistance can correspond to the programmed state ofresistive memory structure 202.

In a number of embodiments, during a read operation, bias generator 129can establish, through read sensing logic 228, a read bias voltagepotential difference between bit line 220 and source line 222, e.g., afixed voltage, associated with memory cell 212. The read bias voltagecan cause a particular magnitude of current to flow corresponding to theresistance of resistive memory structure 202. For example, the greaterthe resistance of resistive memory structure 202, the smaller thecurrent that flows for a given read bias voltage according to Ohm's law.The amount of current flowing through resistive memory structure 202during a read operation (or a voltage proportional thereto) can besensed by read sensing logic 228, e.g., a sense amp (not shown) cancompare a circuit-derived input to a reference input that corresponds toa boundary condition between two programmed states, to determine anoutput corresponding to the programmed state represented by the presentresistance of resistive memory structure 202.

In a number of embodiments, a read current can be applied throughresistive memory structure 202 causing a corresponding voltage to bedeveloped, which can be sensed and compared to a reference voltage. Fromthe comparison, the resistance of resistive memory structure 202 can bedetermined, e.g., based on the principles of Ohm's law.

Although FIG. 2 illustrates, and the discussion above describes, aparticular read and write logic arrangement, one of skill in the artwill appreciate that a number of embodiments of the present disclosurecan be implemented using other configurations of logic for switchingand/or programming resistive memory structure 202. Further, resistivememory 200 can include additional elements and/or circuitry not shown inFIG. 2 so as not to obscure embodiments of the present disclosure, aswill be appreciated by one of skill in the art.

CONCLUSION

Resistive memory and methods of processing resistive memory aredescribed herein. One or more method embodiments of processing resistivememory include conformally forming a cell material in an opening in aninterlayer dielectric such that a seam is formed in the cell material,forming a conductive pathway by modifying the seam, and forming anelectrode on the cell material and the seam.

Although specific embodiments have been illustrated and describedherein, those of ordinary skill in the art will appreciate that anarrangement calculated to achieve the same results can be substitutedfor the specific embodiments shown. This disclosure is intended to coveradaptations or variations of various embodiments of the presentdisclosure. It is to be understood that the above description has beenmade in an illustrative fashion, and not a restrictive one. Combinationof the above embodiments, and other embodiments not specificallydescribed herein will be apparent to those of skill in the art uponreviewing the above description. The scope of the various embodiments ofthe present disclosure includes other applications in which the abovestructures and methods are used. Therefore, the scope of variousembodiments of the present disclosure should be determined withreference to the appended claims, along with the full range ofequivalents to which such claims are entitled.

In the foregoing Detailed Description, various features are groupedtogether in a single embodiment for the purpose of streamlining thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the disclosed embodiments of the presentdisclosure have to use more features than are expressly recited in eachclaim. Rather, as the following claims reflect, inventive subject matterlies in less than all features of a single disclosed embodiment. Thus,the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment.

1. A method of processing a resistive memory cell, comprising:conformally forming a cell material in an opening in an interlayerdielectric such that a seam is formed in the cell material; forming aconductive pathway by modifying the seam; and forming an electrode onthe cell material and the seam.
 2. The method of claim 1, whereinmodifying the seam includes forming a filament in the seam.
 3. Themethod of claim 2, wherein the method includes heating the filamentafter the filament is formed in the seam.
 4. The method of claim 2,wherein the filament is a filament source material.
 5. The method ofclaim 1, wherein the method includes: conformally forming the cellmaterial in the opening such that cell material is formed between abottom of the seam and an additional electrode adjacent the opening; andforming the conductive pathway does not include forming an additionalmaterial that couples the bottom of the seam to the bottom electrode. 6.A method of processing a resistive random access memory (RRAM) cell,comprising: forming a seam in a cell material by conformally depositingthe cell material in an opening in an interlayer dielectric; forming aconductive pathway in the cell material by modifying the seam; andforming an electrode on the cell material and the seam.
 7. The method ofclaim 6, wherein modifying the seam includes forming a filament in theseam.
 8. The method of claim 6, wherein the method includes conformallydepositing the cell material in the opening such that cell material isformed between a bottom of the seam and an additional electrode adjacentthe opening.
 9. The method of claim 8, wherein only cell material isformed between the bottom of the seam and the additional electrode. 10.The method of claim 6, wherein the method includes removing a portion ofthe cell material before forming the electrode on the cell material andthe seam.
 11. A method of processing a resistive memory cell,comprising: conformally forming a resistive memory cell material in anopening in an interlayer dielectric such that a seam is formed in theresistive memory cell material; forming a filament in the seam; andforming an electrode on the resistive memory cell material and filament.12. The method of claim 11, wherein the method includes forming thefilament with a different material than the resistive memory cellmaterial.
 13. The method of claim 11, wherein the method includesdiffusing atoms from the filament into the resistive memory cellmaterial after the filament is formed in the seam and before theelectrode is formed on the resistive memory cell material and filament.14. The method of claim 13, wherein the method includes diffusing atomsfrom the filament by heating the filament.
 15. The method of claim 11,wherein the method includes conformally forming the resistive memorycell material in the opening such that the seam is not in contact withan additional electrode adjacent the opening.
 16. The method of claim11, wherein the method includes forming the filament in the seam suchthat the filament completely fills the seam.
 17. A resistive memorycell, comprising: an interlayer dielectric having an opening; a cellmaterial conformally formed in the opening such that the cell materialincludes a seam; a conductive pathway in the seam of the cell material;and an electrode on the cell material and the conductive pathway. 18.The resistive memory cell of claim 17, wherein the conductive pathwayincludes a filament.
 19. The resistive memory cell of claim 18, whereinthe filament is a metal or a metal oxide.
 20. The resistive memory cellof claim 17, wherein the cell material is a metal oxide.
 21. Theresistive memory cell of claim 17, wherein the conductive pathway has adiameter of 0.5 nanometers to 5.0 nanometers.
 22. The resistive memorycell of claim 17, wherein the opening has a diameter of 10 to 30nanometers.
 23. A resistive random access memory (RRAM) cell,comprising: an interlayer dielectric having an opening; a resistivememory cell material conformally formed in the opening such that thecell material includes a seam; a filament in the seam; and an electrodeon the resistive memory cell material and filament.
 24. The RRAM cell ofclaim 23, wherein the filament is a different material than theresistive memory cell material.
 25. The RRAM cell of claim 23, whereinthe resistive memory cell material is Ge_(x)Se_(y).
 26. The RRAM cell ofclaim 23, wherein: the RRAM cell includes an additional electrodeadjacent the opening in the interlayer dielectric; and an end of thefilament in the seam is a distance of 3 Angstroms to 15 Angstroms fromthe additional electrode.
 27. The RRAM cell of claim 26, wherein theRRAM cell includes only resistive memory cell material between theadditional electrode and the end of the filament.
 28. The RRAM cell ofclaim 23, wherein the filament has a diameter of approximately 1nanometer.
 29. The RRAM cell of claim 23, wherein the filament is afilament source material.